Tag Archives: cretaceous age

According to the Impact Theory, a rock from space smashed into the earth, threw up a huge dust cloud, chilled the atmosphere and sent down acid rain. All the dinosaurs died immediately all over the globe or in a week or so.

So….where are the bodies of the victims?

Probability of Becoming a Fossil: 0% or 100%

0%If you die on a high plateau or a grassy meadow or on the average forest floor, far from the influence of river floods, your bones will get chewed, cracked, smashed and digested by scavengers. The remnants will get dried up and will flake away to nothing under the sun. Or, if the ground is wet, worms and grubs and fungi will destroy your osseous remnants.

That happens to most dead bodies, most spots, most of the time. Or…

100%
What if you’re lucky enough to die in a depositional basin, where yearly floods bring in layers of sand, silt and mud, and where lake bottoms accumulate blankets of sediment all the time. A place where huge sand bars develop in streams and rivers….

….then the possibility that some of your bones will get buried and fossilized rises to close to 100%.

Dino Extinction Supposedly Hit While Montana Was Getting SedimentAt the time of the Great Dino Die-Off, no sediment was being laid down in most places in the world. But in Montana’s Cretaceous coal fields, there were many swampy lakes and sluggish rivers, locales where mud and sand was being carried in. This depositional activity seems to have continued right through the end of the Cretaceous and beginning of the next Period, the Tertiary (“Age of Mammals”).

In fact, field geologists have a hard time telling where the Cretaceous mud ends and rhe Tertiary mud begins.

If the Impact Theory is right, millions of Triceratops carcasses littered the landscape. Tens of millions of duck-bill dino bones also covered the ground. And….there were no big scavengers to crack the bones. The average dino body would last far longer than usual. Some of the impact victims should have had a high probability of being buried in the mud at the Impact Layer, the sand and silt and mud deposited right after the rock from the sky struck.

Total number of dino bones found right at the Impact Layer – 00.00.

That’s one reason why I am an Impact Skeptic. You have to do some special pleading to explain the lack of dino bones at the impact layer. You could argue that soil acid dissolved the bones. Or that for a hundred years there was no new mud, no new sand, no new silt.

Could be.

Still, I like to begin with a geological peshat (first impression): When I scan the actual facts on the ground, there is no evidence whatever of a sudden massive death of dinosaurian multitudes at the Impact Layer.

Evidence for a Long, Slow Disaster
There are clues that indicate the dino ecosystem was deteriorating long before the impact. The diversity among big, multi-ton dinos went way down about 5 to 10 million years before the end. In the Latest Cretaceous (Lancian Age) in most places in Montana, there are only two common big dinos – either Triceratops or the duckbill Edmontosaurus. It was a dino-monoculture. At 76 million years ago diversity was much higher.

Serial Killer in Deep TimeThe biggest reason I’m a skeptic is the victim profile. When the dinos finally went extinct, salamanders, frogs, pond turtles, river gators all survived and thrived. So did most small terrestrial species. That pattern holds for six other mass extinctions – beginning at 285 million ears ago, long before the first dino. And the pattern is obvious in the last extinction at the end of the Ice Age, 11,000 years ago.

Impact Theory Fails to Predict the Correct Victim ProfileSudden chill and acid rain will wipe out salamander-oids and frog-oids and turtle-oids. And hit big, active animals far less severely.

Join us Saturday, Nov. 7 for HMNS Dino Days, a family paleo festival that features fossil related activities and arts and crafts. Museum paleontologist Robert “Bob” Bakker will be on hand to answer any of your dinosaur questions.

This is a great chance for enthusiasts of all ages to come learn and discuss dinosaurs. We encourage you to bring in your own rocks, fossils, and other unique objects for identification. While you are here, take some time to help our volunteers sift through soil to recover bone fragments, teeth, and claws spanning 287 million years of natural history. Some of the Cretaceous age sediments you can sift through come from Texas and may contain fossilized shark teeth – and if so, finders keepers!

“I was first drawn to the shadow when I saw it behind the head of the dinosaur replica. I ended up taking this photo of the replica and shadow. But as I walked past the head, I saw that the entire dinosaur body threw this wonderfully detailed shadow on the wall. Every time I look at it I feel like the dinosaur is trying to sneak up on me.”

This photo was taken in our new exhibition Dinosaur Mummy CSI: Cretaceous Science Investigation, and the dinosaur laanba is referring to is Leonardo, one of the best preserved dinosaurs ever discovered. The shadow is cast by a replica of what Leonardo would have looked like, walking past you 77 million years ago – it’s a model based heavily on the fossil, which has fossilized skin and preserved internal organs. You can see both – the fossil and the very sneaky replica laanba has captured so vibrantly – through Jan. 11, 2009.

So, what’s this Photo of the Month feature all about? Our science museum is lucky enough to have talented and enthusiastic people who visit us every day – wandering our halls, grounds and satellite facilities, capturing images of the wonders on display here that rival the beauty of the subjects themselves. Thankfully, many share their photos with us and everyone else in our HMNS Flickr group – and we’re posting our favorites here, on the Museum’s blog, once a month. (You can check out all our previous picks here or here.)